نوع مقاله : مقاله پژوهشی
نویسندگان
گروه مهندسی علوم باغبانی و فضای سبز، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The natural forest landscape emerges from complex interactions among biological structures, ecological processes, and human perceptual patterns. Tree allometric traits, as quantitative indicators of growth, extend beyond conventional forest metrics and function as key generators of landscape spatial structure. This study aims to clarify the role of native tree allometric characteristics in shaping the quality of spatial structure in natural landscapes and in establishing the conditions necessary for coherent landscape perception.
The research follows an analytical–explanatory framework and relies on secondary allometric data. Diameter at breast height (DBH) and species specific allometric coefficients are considered independent variables, while root biomass and rooting depth serve as mediating variables. The dependent variable is the quality of landscape spatial structure. Root biomass of dominant Hyrcanian forest species was estimated using power law allometric models, and rooting depth data were derived from reliable empirical sources. The causal relationships among allometric traits, substrate stability, vegetation establishment patterns, and landscape spatial structure were subsequently examined.
The results demonstrate that increases in DBH lead to nonlinear growth in root biomass and root system extent. Through enhanced soil shear resistance, reduced erosion, and greater stabilization of vegetation cover, these changes contribute to the formation of spatially stable forest patterns. Such physical stability provides the foundation for continuity of vertical layering, visual legibility, and spatial scalability, which are essential prerequisites for coherent perception of natural landscapes. This study conceptualizes tree allometry not merely as a biological indicator, but as a fundamental structural mechanism in natural landscape formation, underscoring its significance for forest landscape analysis, conservation, and management.
کلیدواژهها [English]
Extended Abstract
Introduction
Forest landscapes are the outcome of complex interactions among biological structures, ecological processes, and human perceptual experiences. The Hyrcanian forests, due to their geological antiquity, high species diversity, and location on steep terrains, represent one of the most valuable forest ecosystems globally. These forests, among the oldest in the Northern Hemisphere, exhibit unique characteristics such as vertical stratification, heterogeneous species composition, and relative resilience to environmental changes. Tree allometric traits, including diameter at breast height (DBH), height, crown volume, and root depth, serve not only as indicators of growth and ecosystem performance but also play a critical role in shaping the spatial structure of natural landscapes. These traits are instrumental in assessing ecological health and, importantly, in determining the perceptual and experiential quality of forested spaces for humans. Despite extensive ecological and forest-science studies on Hyrcanian forests, few investigations have simultaneously examined the relationship between tree allometry and landscape perception. This study aims to elucidate the role of native tree allometric traits in forming spatial quality and facilitating an integrated perceptual experience of the natural landscape, providing a comprehensive conceptual and analytical framework for sustainable forest landscape management.
Material and Methods
This research employed an analytical–explanatory approach with a mixed quantitative–qualitative perspective. Allometric data were obtained from reliable secondary sources, including species-specific allometric coefficients and standardized DBH values. Sample sites included Shast Kalateh and Naharkhoran in Golestan Province, and Siah-Daran in Ramsar, representing diverse species composition and relatively undisturbed conditions. Independent variables included DBH and species-specific allometric coefficients, mediating variables included biomass and root depth, and the dependent variable was spatial structure quality. Root biomass was estimated using power allometric models, while root depth data were extracted from validated empirical sources. Environmental factors such as slope, soil type, and surface moisture were considered to ensure accurate spatial structure analysis from a substrate stability perspective. The causal chain among allometric variables, substrate stability, vegetation distribution patterns, and spatial structure quality was analyzed to examine both direct and indirect relationships.
Results and Discussion
The results indicated that increases in DBH non-linearly enhanced biomass accumulation and root system expansion, which, through improving soil shear resistance, reducing erosion, and stabilizing vegetation cover, contributed to the formation of sustainable spatial patterns in the forest. Dominant species, such as Quercus (oak) and Alnus (alder), exhibited the highest root biomass and most significant effects on soil stabilization and vegetation maintenance. This physical substrate stability facilitated vertical stratification continuity, visual legibility, and spatial scalability, serving as prerequisites for integrated landscape perception. Combined data analysis revealed that native species not only provide ecological functions but also shape perceptual experiences. The spatial distribution, crown form, and tree height, in combination with climatic factors such as light, mist, and humidity, generated structured visual patterns that create rhythm and predictability in spatial perception. Furthermore, analysis of height and species distribution patterns demonstrated that spatial arrangements significantly influence perceived landscape coherence, visual quality, and the sense of physical stability. These findings highlight that understanding natural landscapes extends beyond aesthetics, encompassing strong links between ecological stability, root depth, and biomass, which can guide practical conservation and management strategies.
Conclusion
This study demonstrates that tree allometric indicators in Hyrcanian forests are systematically and significantly related to spatial structure quality and landscape perception. Species such as Alnus and Quercus, due to their structural and growth characteristics, play key roles in soil stabilization, erosion control, and the perceptual organization of landscapes. The findings emphasize that the Hyrcanian natural environment is not merely a passive object of observation but an active agent in natural landscape formation. Practical applications include forest landscape design and sustainable management, where species selection based on allometric traits can simultaneously enhance ecological and perceptual objectives. Future research is recommended to include a wider range of species and employ advanced perceptual assessment methods, such as eye-tracking or realistic modeling, to further clarify the relationship between spatial structure and human experience.
Author Contributions
Salimi M. and Atashinbar M. conceived and planned the experiments. Salimi M. carried out the experiments, performed the laboratory work, and collected the data. Atashinbar M. contributed to data analysis and interpretation of the results. All authors provided critical feedback and helped shape the research, analysis, and manuscript.
Data Availability Statement
The authors declare that all the data supporting the findings of this research are available within the article.
Ethical considerations
This article does not contain any studies involving human and animal subjects.
Conflict of interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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